For completeness, a comparison against turboshafts aimed at helicopter application:
Rolls-Royce Helicopter Turboshaft Database
AE 1107C: 4586 kW / 440 kg = 10.4 kW/kg
RTM332: 1897 kW / 228 kg = 8.32 kW/kg
T800: kW 1268 / 154 kg = 8.23 kW/kg
MTR392: 958 kW (Max Take-off) / 169 kg (dry) = 5.57 kW/kg
Gem: 746 kW (Max Take-off )/ 183 kg (dressed) = 4.08 kW/kg
250: 485 kW / 124 kg = 3.91 kW/kg
T63: 313 kW / 72 kg = 4.35 kW/kg
In practice figure on a increase on cost/power proportional to power/weight...
Mart